Addresses a bug where Token.waitForCompletion hangs forever when the …

[fnordian]

…broker closes connections quickly after accepting it

Please make sure that the following boxes are checked before submitting your Pull Request, thank you!

• This change is against the develop branch, not master.
• You have signed the Eclipse ECA
• All of your commits have been signed-off with the correct email address (the same one that you
  used to sign the CLA) Hint: use the -s argument when committing.
• If This PR fixes an issue, that you reference the issue below. OR if this is a new issue that
  you are fixing straight away that you add some Description about the bug and how this will fix it.
• If this is new functionality, You have added the appropriate Unit tests.

Fixes issue #1013

[zhubinsheng]

Hello，Under what circumstances would this error occur？